In a principal aspect the present invention relates to an extractor tool designed to engage fasteners including Torx brand fasteners, particularly those fasteners which have been damaged in some fashion wherein the flutes of the fastener drive opening do not conform with the standard design requirements for the Torx brand or a similar type fastener.
Fasteners for assembly of various mechanical devices typically include a head with an axial shaft that projects from the head. The shaft may be threaded or otherwise configured to provide an attachment feature. The head is usually configured to have a diameter or shape or configuration which exceeds the size and configuration of the transverse dimension of the shaft. Typically the head of the fastener will include a keyed center opening into which a tool may be inserted to effect a fastening operation. Preferably the opening in the head of the fastener is such that the fastener may not only be inserted or driven into stock material by a tool, but also may be removed by the same tool when desired for replacement, repair or the like.
A problem often observed with fasteners of various design is the degradation of the drive opening associated with the head of the fastener. For example, with respect to a Phillips head fastener, the flutes which are to be engaged by a Phillips type screwdriver may degrade and thereby preclude easy removal of the fastener. The same circumstance may occur with respect to Torx brand fasteners as well as other types of fastener products.
To address this circumstance, various patents describe fastener extraction tools which may be used for extraction of broken or degraded fasteners. Following is a list of patents which disclose such tools and methods for extraction:
Patent No.Issue DateInventorTitle4,777,850Oct. 18, 1988PolonskyDrill-Out ThreadedBroken Bolt Extractor5,031,487Jul. 16, 1991PolonskyBroken Bolt Extractor5,251,516Oct. 12, 1993DesaulniersTool for ExtractingBroken Bolts and theLike5,906,146May 25, 1999ArlenApparatus and Methodfor ExtractingBroken ThreadedMembers6,098,499Aug. 8, 2000PoolBolt Extraction Tool6,761,089Jul. 13, 2004BergamoTool for RemovingScrews with DamagedHeadsU.S. Publi-PublicationLiuTool Having a Structurecation No.Datefor Removing Damaged2003/0136228Jul. 24, 2003ScrewsA1
Various products available in the marketplace designed to effect extraction of fasteners include the following:
Spiral Flute Screw Extractors by Irwin Industrial Tools
Alden 8440P 4-Piece Grabit Broken Bolt and Damaged Screw Extractors Set
Extractor, Multi-Spline, 11/32″ and ¼″ by Snap-on
Screw & Bolt Extractors made in Germany by Elora Werkzeugfabrik
Blackhawk DT-55 Screw Extractor Set sold by Grainger
Seven Piece Square Easy Out Set Screw Extractor by Desco USA
Nonetheless difficulties are encountered when attempting to effectively remove various types of fasteners having drive openings that degrade or are otherwise damaged.